The present invention relates generally to coated potato products and formulations for coating potato products such as frozen french fries.
Methods for preparing and applying coatings to the outer surfaces of frozen potato products are well known in the art. Murray et al. U.S. Pat. No. 3,597,227 disclose a process in which raw potato strips are coated in a hot aqueous solution of modified gelatinized amylose derived from corn or potato starch. The process is said to produce a finished product which has superior strength and rigidity. Van Patten et al., U.S. Pat. No. 3,751,268 disclose the coating of blanched potato pieces with an ungelatinized unmodified high amylose starch having an amylose content of at least 50 percent. The coated potato strips are deep fat fried during which the starch in the coating is gelatinized.
El-Hag et al. U.S. Pat. No. 4,317,842 discloses the process of dipping blanched potato strips in an aqueous ungelatinized starch slurry to coat the strips, which are next soaked in hot oil to gelatinize the starch in the coating. The strips are then parfried and frozen. The strips may be reheated for consumption by heating in an oven rather than by deep fat frying.
Lenchin et al., WO 85/01188 disclose batters comprising the flour of high amylose corn hybrids for producing microwaveable pre-fried foodstuffs. The use of flours of high amylose corn hybrids is said to provide pre-fried foodstuffs with improved crispness after microwave cooking which otherwise tends to make such products soggy.
Sloan et al., U.S. Pat. Nos. 5,059,435 and 5,141,759 disclose a process for preparing frozen coated potatoes wherein raw potatoes are washed, cut, blanched and partially dehydrated. The cut potatoes are then coated with an aqueous starch slurry comprising 15 to 35% by weight modified ungelatinized potato starch, 2 to 10% by weight modified ungelatinized corn starch, 2 to 10% by weight rice flour and other optional ingredients. The coated potato strips are parfried in oil and then frozen. The frozen strips are prepared for consumption by either finish frying in hot oil, or heating in an oven. The starch coating is said to enhance the holding quality of the ready to consume product and to improve the acceptability of the finished product by increasing the crispness of the outer surface, and helping to maintain the tenderness of the interior of the cut potato. In particular, the potato starch and corn starch are each said to contribute crispness to the coating, and because they are not gelatinized prior to the parfrying step they decrease clumping of the strips during processing. The rice flour is said to provide a desirable tenderness in the finished product.
The Sloan patents teach the use of potato starches which have been modified through known chemical cross-linking processes in order to minimize sticking or clumping of the strips during processing, and coat the potato strips evenly. The Sloan patents disclose as preferred an ungelatinized chemically modified potato starch (K-1010, Penford Corporation, Richland, WA) which is crosslinked with phosphorus oxychloride (POCl.sub.3) at an effective level of 980 ppm. (This starch is characterized by a Brabender Amylograph viscosity of 50-100 BU ("Brabender units") when measured at a 9% starch solids concentration for 15 minutes at 95.degree. C.) A chemically modified ungelatinized cornstarch said to be preferred for use in conjunction with the above modified potato starch is said to be Flojel.RTM. (National Starch and Chemical Corp., Bridgewater, N.J.) which is said to contribute crispness to the coating and to produce an optimal result when present in the coating slurry at a concentration of between two and ten percent by weight.
Also of interest to the present application is the disclosure of co-owned U.S. Pat. No. 5,648,110 which discloses use of potato starches with selected crosslinking levels as preferred components of starch enrobing slurries. Specifically, the patent discloses that potato strips coated with an aqueous starch enrobing slurry having an as is solids content comprising not less than about 50% by weight of ungelatinized crosslinked potato starch characterized by a viscosity of from 200 to 1100 Brabender Units (BU) when measured at 9% solids concentration after 15 minutes at 95.degree. C. (which corresponds to a crosslinking level of from 550 to 900 ppm using POCl.sub.3) and from 10 to 25% by weight rice flour provide improved crispness and texture properties. Also of potential interest to the present application is co-owned and copending U.S. patent application Ser. No. 08/822,031 filed Mar. 24, 1997, now abandoned which is a continuation-in-part of U.S. Pat. No. 5,648,110 and discloses the use of not less than about 50% by weight of ungelatinized crosslinked potato starch characterized by a viscosity of from 200 to 1100 Brabender Units and up to 45% by weight rice flour provided improved crispness properties. Also of potential interest to the present application is co-owned U.S. Pat. No. 5,750,168 the disclosure of which is hereby incorporated by reference which is directed to starch enrobing slurries having a solids content comprising not less than 20% by weight ungelatinized crosslinked tapioca starch characterized by a crosslinking level of from 300 to 1000 ppm. The patent teaches the incorporation of rice flour as a component of the enrobing slurries at solids contents preferably ranging from 10% to 25%.
Despite the many advances in the french fry coating art there nevertheless remains a need for improved enrobing slurries characterized by improved crispness, holding and flavor properties.